Swimming Creatures Lesson 1 - Aquatic Animals

Monday, January 12, 2009

In our first lesson, we read that swimming animals are called aquatic animals because aqua comes from the Latin word meaning "water." We learned about aqua mobility, what nekton means (animal that swims), and what benthos means (animals that don't swim, but scurry, crawl, hop, scoot, burrow or slither across the bottom of the ocean. We found out that some benthic animals are also sessile (they just sit there!). The boys were surprised to learn what plankton are - creatures that wander or drift. They learned there are two kinds - phytoplankton (which make their own food using the sun) and zooplankton (which need to eat to get their food). It was fun to learn that plankton can be microscopic or as giant as a blue whale!
The section on filter feeders was interesting to me. Filter feeders are creatures that God created to clean up the oceans and rivers of the world. They are the "cleaning crew" of the waters. Filter feeders take in contaminated water and spurt out clean water. I found this interesting because we as a family eat only foods that God calls "clean." And filter feeders are not clean! God created these special cleaners to clean up the ocean to provide a clean environment for food we can eat - whatever has fins and scales.
This lesson also focused on the environment that the creatures we will be studying live in, like ocean currents. We read that surface currents are formed by winds and form circular patterns called gyres. We did a fun "Try This!" demonstration to create a miniature gyre!

We filled a dish with confetti and blew air on opposite sides of the dish in opposite directions. The air blowing on the surface of the water in opposite directions is just how winds on the earth produce gyres.
For fun, we got out our geography notebooks to read what we wrote on ocean currents last year. Nathan read his first, and he said, "I wrote that?" (He did a good job explaining how currents affect weather).
We learned that deep ocean currents are called thermohaline currents because they are formed by heat (thermo) and salt (haline). We learned about tides and what causes them (the moon).
We got a laugh over the section titled "Planet Water." Author Jeanie Fulbright states, "If you look down at the earth from space, you can see that the earth should have been named "ocean" instead of "earth" for the whole earth is mostly ocean!"
Then we did some more geography review and named the four oceans and looked at a globe to see which hemisphere is covered with the most ocean and which is covered with the most land. We read some fresh water facts and vocabulary like, brackish (salty) and estuary (where a river meets with an ocean or sea) and what the head and mouth of a river are (all but brackish were review for us). Speaking of brackish, did you know that the amount of salt in the oceans indicates that the earth's oceans (and the earth itself) are very young? If the earth were really billions of years old, there would be much, much more salt in the ocean because rivers and volcanoes dump salt into the ocean and there is no where for it to go!
We learned what the 4 zones of the ocean floor are: continental shelf, slope, rise and abyssal plain; and what the 3 zones in which aquatic creatures live: the sunlit zone, the twilight zone, and the midnight zone. We read about the abyss and animals that live there and why we cannot go there! (Because of water pressure) We did a "Try This" activity to understand why. We blew up a balloon inside of a bottle, tied it and pushed it in the bottle. Keeping the balloon at one end, we had Jordan step on and off the bottle while we observed the balloon.

When he stepped on the bottle, the balloon got smaller! (It took us a couple minutes to figure this out). When he stepped off, the balloon got bigger. This happened because of air pressure. Stepping on the bottle stimulates what happens to your lungs when you dive deep down in the ocean. They get smaller. When Jordan lifted his foot off the bottle, the balloon got bigger because the pressure was relieved!
The boys then worked on their notebooking, writing and illustrating all that they remembered.(I am "notebooking" as I type this post -it is good for me to remember too!)
Dylan's:

Nathan's:
Jordan's:
(Sorry for the poor quality, I have not figured out how to work my new scanner yet! If you click on the picture, you may be able to see them better.)
Well, we finally got to make our ocean boxes! First we made a box out of a heavyweight poster board to make our ocean box. Then we decorated them with foam aquatic animals.

The finished boxes.
Then we did an experiment to see which is heavier, cold water or hot water. Using our Scientific Speculation Sheets, we first made our hypothesis. Then, we put hot water in the big bowl with blue food coloring, put cold water in a plastic cup with yellow food coloring, cut a small hole in the bottom, placed the cup in the bowl and let the water run out the bottom. You can see the the colder (yellow) water sank to the bottom!

Then we tried it again, with the cold (blue) water in the big bowl and the hot (yellow) water in the cup.
The yellow water did not sink this time. Instead the yellow water mixed with the blue water making green water! We learned that cold water is heavier than warm water!